Istanbul is 7 hours ahead of Atlanta
Best overlap: 8:00 AM to 11:00 AM in Atlanta is 3:00 PM to 6:00 PM in Istanbul.
If you set up a recurring sync, 8:00 AM to 11:00 AM in Atlanta (3:00 PM to 6:00 PM in Istanbul) is the natural home for it. You share roughly 3 hours a day. That's enough for regular meetings, but treat the window as prime time and guard it. Keep an eye on the calendar — Atlanta observes daylight saving and Istanbul doesn't, which nudges this window by an hour twice a year.